According to new research, chronic exposure to low levels of lead, cadmium and arsenic which can be found in household items, has been found to cause an increased risk of stroke.
This new research highlights clinical and public health implications, as well as stating that current traditional risk factors for cardiovascular diseases such as stroke, do not currently include environmental toxicants.
The field of environmental cardiology identifies exposure to pollutants including contaminant metals as modifiable risks for cardiovascular disease.
Gervasio A. Lamas, M.D., FAHA, chair of the statement writing group and chairman of medicine and chief of the Columbia University Division of Cardiology at Mount Sinai Medical Center, says: “Large population studies indicate that even low-level exposure to contaminant metals is near-universal and contributes to the burden of cardiovascular disease, especially heart attacks, stroke, disease of the arteries to the legs and premature death from cardiac causes.
Vice chair of the statement writing group Ana Navas-Acien, M.D., Ph.D., a professor of environmental health sciences at Columbia University’s Mailman School of Public Health and the director of the Columbia University Northern Plains Superfund Research Program in New York City, says: “These metals interfere with essential biological functions and affect most populations on a global scale.
“After exposure, lead and cadmium accumulate in the body and remain in bones and organs for decades. In the U.S. alone, one large study suggested that more than 450,000 deaths annually could be attributed to lead exposure.”
Where can you be exposed to these contaminants?
Exposure to contaminant metals most often occurs involuntarily, through everyday activities. Lead can be found in items such as paint in older homes, tobacco products, second-hand smoke, contaminated foods (ground water and some pottery, ceramics and kitchenware are sources of lead contamination in food), water pipes, spices, cosmetics, electronics and industrial emissions. Cigarette smoking is a source of both lead and cadmium.
Cadmium can be found in nickel-cadmium batteries, pigments, plastic, ceramics and glassware, and construction products. Industrially produced fertilisers use phosphate rock that is naturally rich in cadmium, which then contaminates root vegetables and leafy green plants (including tobacco).
Exposure to arsenic primarily occurs through groundwater which affects drinking water, soil and food grown in contaminated soil. Notably, arsenic builds up oil rice more than other food crops.
According to this research, exposure and risk occurs across diverse populations regardless of socioeconomic level, it is also noted that some people experience greater exposure to toxic metals.
Risk of exposure is higher for those who live closer to major roadways, industrial sources and hazardous waste sites; reside in older houses; or in areas where environmental regulations are poorly enforced and responses to community complaints are inadequate.
Navas-Acien, says: “This is a global issue in which lower-income communities are disproportionately exposed to toxic metals through contaminated air, water and soil.
“Addressing metal exposure in these populations may provide a strategy to reduce cardiovascular disease disparities and advance environmental justice.”
How do contaminant metals increase stroke risk?
- A 2018 review published in the British Medical Journal assessed 37 studies representing nearly 350,000 people from more than a dozen countries. The review reported that higher urine levels of arsenic and blood levels of lead and cadmium were associated with 15-85 per cent higher risk for stroke and heart disease.
- One study in China found that higher levels of lead in the blood were associated with carotid plaque in people with Type 2 diabetes. Another found that cadmium and arsenic were associated with a higher rate of heart disease and ischaemic stroke.
Addressing contaminants in the environment
The writing group behind this research suggest that monitoring environmental metal levels and testing for metal in individuals could be key steps to implement appropriate public health initiatives.
The statement authors note that decreasing metal exposure in tobacco, protecting community water systems and wells, and minimizing metal contamination in air, food and soil are all examples of public health measures that may reduce exposure to metals.
Lamas, says: “Cardiovascular health may be improved with a multi-pronged approach that recognises environmental cardiology and includes environmental monitoring and biomonitoring of contaminant metals; controlling for sources of exposure; and developing clinical interventions that remove metals or weaken their effects on the body.”
